Portable manual knife sharpener



FIG. 1 is a side elevational view of a portable manual knife sharpener showing our new design with the opposite side being a mirror image;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left end elevational view thereof;

FIG. 4 is a right end elevational view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a portable manual knife sharpener, as shown and described. 